Device for detecting and warning the unused state of a vehicle seat belt

ABSTRACT

A device for detecting and warning the unused state of a vehicle seat belt, comprising a detecting circuit having seat switches adapted to be closed on sensing the occupation of the seats and belt switches adapted to be opened by drawing out a given length of seat belt to wear.

United States Patent US] 3,693,147 Seo et al. [45] Sept. 19, 1972 [54]DEVICE FOR DETECTING AND [56] References Cited WARNING THE UNUSED STATEOF A UNITED STATES PATENTS VEHICLE SEAT BELT 3 506 305 4/1970 E' J l340/52 E ieneman, r. eta [721 P 3,375,495 3/1968 Burns .540/52 E Kmfla"bah Japan 3,455,410 7/1969 Wilson ..340/278 [73] Assignee: KabushlkiKeisha Tokai Rlka Denld seisakmho, wishikasugai.gun, Aichi PrimaryExaminer-John W. Caldwell Prefecture Japan Assistant Examiner-GlenSwann, Attorney-Woodhams, Blanchard & Flynn [22] Filed: Jan. 20, 1971[21] Appl. No.: 107,935 CT A device for detecting and warning the unusedstate of [30] Foreign Application priority Data a vehicle seat belt,comprising a detecting circuit having seat switches adapted to be closedon sensing the Jan. 21, 1970 Japan ..45/6234 occupation of the Seats andbe Switches adapted to be opened by drawing out a given length of seatbelt [52] US. Cl. ..340/52 E, 340/278 to wean [51] Int. Cl. ..B60q 1/00[58] Field of Search ..340/52 E, 278

2 Claims, 9 Drawing Figures PATENTEDSEPIQIQR V 3 3693.147

sum 1 are I PATENTEDSEP 19 mm 3.693; 147

sum 2 or 3 INVENTORS /f/K0 AAZA/ 5w msw/x/wa #AMM/ ATTORNEYSP'ATENTEDSEP 19 m2 3.69314 SHEET 3 OF 3 INVENTORS mm/$7 M ATTORNEY .5

DEVICE FOR DETECTING AND WARNING THE UNUSED STATE OF A VEHICLE SEAT BELTFIELD OF INVENTION This invention relates to a device in an automobilefor detecting and warning the unused state of a seat belt and moreparticularly to a device in an automobile provided with seat belts notonly on a drivers seat but also on other passenger seats, which, if atleast one of the occupants of the seats provided with seat belts doesnot use a seat belt, keeps a detecting circuit in a closed state therebyto give him warning to wear his seat belt.

BACKGROUND OF THE INVENTION Though it is prescribed in a law that a seatbeltshall be provided in an automobile, in fact, only few persons useit. Therefore, it has not actually served to prevent death or injurywhen an accident occurs.

In this connection, it is to be noted that the present invention is onewhich enables an alarming means such as an alarming buzzer to be kept onoperating or makes it impossible to start an automobile if all ofoccupants who sit down on seats provided with seat belts dont use therespective seat belts to make a drive safe.

It is an object of the present invention to provide a device effectiveto call upon an occupant of an automobile to wear a seat belt.

SUMMARY OF THE INVENTION According to the present invention, there isprovided a device in an automobile for detecting and warning the unusedstate of a seat belt which comprises a a power source, a power-offswitch connected in series with said power source, an alarming meansconnected in series with said power-off switch, and a detecting circuitconnected in series with said alarming means and divided into at leasttwo branch circuits. One of the branch circuits includes a seat switchprovided in a drivers seat and adapted to be closed on sensing theoccupation of the drivers seat and a belt switch associated with thedrivers seat belt and adapted to be opened on sensing the drawing-outmotion of a given length of the seat belt. The other branch circuitincludes the seat switch provided in the drivers s seat, another seatswitch provided in a passengers seat and adapted to be closed on sensingthe occupation of the passenger seat, and another belt switch associatedwith the passengers seat belt and adapted to be opened on sensing thedrawingout motion of a given length of the seat belt.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be betterunderstood from the following description taken in connection with theaccompanying drawings in which:

FIG. 1 is a vertical cross sectional view of one embodiment of a seatbelt unit employed in the present invention taken along line I-I of FIG.2 with part of it cut out;

FIG. 2 is a vertical longitudinal sectional view of the same taken alongline II--II of FIG. 1,; and

FIGS. 3 to 9 are diagramatical views showing operating states of thedevice according to the present inventIon.

DETAILED DESCRIPTION 0 said winding shaft is provided a spring 16 whichis urged to retract the belt 14 when said belt 14 is drawn out,therebypermitting automatic retracting of the belt 14. To a centralshaft 15' protruding from the side of the winding shaft 15 at itscentral portion is fitted a pinion 17 adapted to rotate together withsaid shaft 15 In said reel case 13 are further provided a movable plate18 having a rack 19 which engages with said pinion l7 and adapted tomove linearly, and a movable contact plate 20 of the belt switch SWwhich is adapted to move slidingly. A projection 11 is provided on thecontact plate 20 and engages with said movable plate 18. Thus, when agiven lengthof the belt 14 is retracted into the reel case 13 by meansof the winding shaft 15, the belt switch is closed. On the other hand,when a given length of the belt 14 is drawn out from the reel case 13,the rack 19 and resultantly the movable plate 18 and the contact plate20 are moved in the direction of an arrow of FIG. 1 by means of thepinion 17 which rotates with the winding shaft 115, to open the beltswitch SW.

Referring now to FIGS. 3 to 8,. there are illustrated operatingconditions of a device according to the present invention, in whichnumeral 1 designates a power source and numeral 2 indicates a detectingcircuit having two branches 2a and 2b. A power-off switch, such as anignition switch 3 and an alarm means 4, such as an indicating lamp or abuzzer, are connected between the detecting circuit 2 and the powersource 1. Numeral 5 designates a seat switch provided in a drivers seatand adapted to be closed on sensing the occupation of the seat. In thepresent embodiment, the seat switch 5 has two sets of contacts 6a and 6bwhich are connected in parallel with each other and included in thebranch circuits 2a and 2b, respectively. In the branch circuit 2a havingthe contact 6a is included a belt switch SW which is adapted to beopened when a given length of the seat belt of the drivers seat is drawnout. Numeral 7 designates a seat switch for a passenger seat other thanthe seat for the driver, which has a contact adapted to be closed onsensing the occupation of the seat. The circuit branch 2b has a beltswitch SW connected in series with the seat switch 7, which belt switchSW is adapted to be read opened when a given length of the seat belt ofsaid seat is drawn out.

' OPERATION As illustrated in FIG. 3, in case both the drivers seat andthe passenger seat are occupied by the respective occupants to close theseat switches 5 and 7 and if both the seat belts are not drawn out to beused, the belt switches SW, and SW are kept in a closed position, sothat, when the ignition switch 3 is closed as shown in the drawings, thecomplete detecting circuit 2 is closed to drive the indicator 4.

As shown in FIG. 4, in case the seat belt of the drivers seat is drawnout and used by the occupant to open the belt switch SW but the seatbelt of the passenger seat is not drawn out, the detecting circuitbranch 2a is kept closed to operate the alarm means 4. While, as shownin FIG. 5, in case the seat belt of the passenger seat is used to openthe belt switch SW, and the seat belt of the drivers seat is not drawnout, the detecting circuit branch 2a is kept closed for operating thealarm means 4.

As shown in FIG. 6, in case the seat belts of both the drivers seat andthe passenger seat are used, the belt switches SW and SW, are opened andthe detecting circuit 2 is resultantly opened to prevent the operationof the indicator or alarm 4.

In case only the drivers seat 5 is occupied and the passenger seat isnot occupied as seen in FIGS. 7 and 8, the seat switch 7 is kept openedand the branch circuit 2b is therefore opened. In case the seat belt ofthe drivers seat is not used, the belt switch SW is kept in a closedposition as shown in FIG. 7 to retain the detecting circuit branch 2aoperative to actuate the indicator 4. Whereas, in case the seat belt isused by the driver to open the seat switch SW, as shown in FIG. 8, thedetecting circuit branch 2a is opened to prevent the operation of theindicator 4. As shown in FIG. 9, in case the seat for the driver is notoccupied, the whole circuit is in an open or OFF condition independentof the condition of the belt switch SW and accordingly the alarmingmeans 4 is not operated.

While in the present embodiment, two sets of contacts 6a and 6b areemployed in the seat switch 5 of the drivers seat, one set of contactsis sufficient for the purpose.

Thus it can be appreciated that the present invention provides a devicewhich can perform accurate detection of the unused state of a seat beltin case a driver alone or a plurality of occupants are in an automobileand occupy respective seats provided with seat belts and if all of theoccupants dont use the respective seat belt, and eliminate confirmationprocedure whether each of the occupants wears a seat belt or not,thereby permitting safe driving.

What is claimed is:

1. A system for a vehicle for detecting and indicating the unused stateof seat belts, comprising:

a power source;

a power-off switch connected in series with said power source;

alarm means connected in series with said power-off switch; and

a detecting circuit connected in series with said alarm means anddivided into at least two parallel branch circuits, said detectingcircuit including first normally open switch means associated with thedrivers seat and adapted to be closed on sensing the occupation of thedrivers seat, said first switch means being associated with both of saidbranch circuits;

one of said branch circuits including second normally closed switchmeans coacting with the seat belt associated with the drivers seat andadapted to be opened on sensing the drawing out motion of a given lengthof the seat belt, said second switch means being connected in serieswith said first swit hmeans; the other branch circuit including thirdnormally open switch means associated with a passengers seat and adaptedto be closed on sensing the occupation of the passengers seat, andfourth norm ally closed switch means coacting with the seat beltassociated with the passengers seat and adapted to be opened on sensingthe drawing-out motion of a given length of the seat belt, the third andfourth switch means being connected in series with one another and inseries with said first switch means. 2. A system according to claim 1,wherein said first switch means includes two sets of contacts contactsconnected in parallel with one another and in series with said alarmmeans, one set of contacts being included in one of said branch circuitsand the other set of contacts being included in the other of said branchcircuits.

1. A system for a vehicle for detecting and indicating the unused stateof seat belts, comprising: a power source; a power-off switch connectedin series with said power source; alarm means connected in series withsaid power-off switch; and a detecting circuit connected in series withsaid alarm means and divided into at least two parallel branch circuits,said detecting circuit including first normally open switch meansassociated with the driver''s seat and adapted to be closed on sensingthe occupation of the driver''s seat, said first switch means beingassociated with both of said branch circuits; one of said branchcircuits including second normally closed switch means coacting with theseat belt associated with the driver''s seat and adapted to be opened onsensing the drawing out motion of a given length of the seat belt, saidsecond switch means being connected in series with said first switchmeans; the other branch circuit including third normally open switchmeans associated with a passenger''s seat and adapted to be closed onsensing the occupation of the passenger''s seat, and fourth normallyclosed switch means coacting with the seat belt associated with thepassenger''s seat and adapted to be opened on sensing the drawing-outmotion of a given length of the seat belt, the third and fourth switchmeans being connected in series with one another and in series with saidfirst switch means.
 2. A system according to claim 1, wherein said firstswitch means includes two sets of contacts contacts connected inparallel with one another and in series with said alarm means, one setof contacts being included in one of said branch circuits and the otherset of contacts being included in the other of said branch circuits.